Buderus GB142 Series HX Cleaning Methodology or Process

GB142

I have read so many threads about the GB142 HX getting clogged with build up, i.e. like calcium. In addition, I have read many services techs approach or methods to cleaning them.

Even very experienced techs, seem to try and just manually scrape or chip away the deposits. It can be effective, but time-consuming. If the proper approach is not used one could also damage the fins or even the tubes. I recently opened mine up and scraped the top half with a credit card cut in half to get into the 45-degree angles. It worked well even for a basic clean, but I would prefer a better method.

I have read about using mineral oil for years and have had a bottle of baby oil ( mineral oil with fragrance) sitting next to my unit for at least 5 years. I have never used it but would like to finally try.

Based on my research, it seems that one should put the mineral oil in a spray bottle and spray inside the and around the HX, while avoiding the igniter and sensors. Then close the unit and run high for 10-15 minutes. Let cool then clean. I have never seen a video of this though. Can someone tell me if the deposits soften or turn to an ashlike material, similar to what happens with a self-clean oven?

Does anyone out there have step-by-step instructions explaining how this should be done properly and what to expect for results?

GW

We used mineral oil for years, and then somebody at Bosch Buderus told to stop doing that. It’s one of the drawbacks of this boiler, I can really get clogged up badly. I’ve never seen a step-by-step or a video myself. My service man takes care of all these tuneups for my company.

HVACNUT

They also state in the service manual to not use inhibitors or additives which I found odd. CYA I guess. 

Alan (California Radiant) Forbes

I followed this video the last time I cleaned one. I used mineral oil, but from what Gary says above, I'd check with Bosch Buderus to find out what to use instead. 603-552-1100

https://www.youtube.com/watch?v=fZTu37sEELg&list=PLq4NGiyqj85YbH1rMZ1lfRFwEj4kkmFxb&index=6

kcopp

Axiom makes some good products to assist w/ this.... https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Axiom-AXTH-CF9-AL-Product-Overview.pdf

GW

Maybe it was the rep that told me, I really don’t recall.

woobagooba

I used that video to perform a cleaning on my 142 last years. Gary thanks again for helping me nurse it through another winter.

I'm now replacing that 142. Its available for parts. HX is near end of life, but otherwise useful for parts. Drop me a message if you are interested. Cheers

GB142

Wow, that Video was great. I watched some other videos of theirs, but could not locate that one. I just looked up AXI-Therm CF9-AL solution's MSDS which shows it is Sodium Hydroxide 7-13%.

HOLY CRAP THOUGH. Supply house sells it for $96 for 33oz!!!!

I think I may try the baby oil first or try and find sodium hydroxide in another form.

I know that my boilermate indirect hot water tank has aluminum fins. I run a well and every 1 year need to clean it. They recommend either lots of vinegar or Sodium Phosphate Solution (what's used for ice machines).

What does the Chimney Sweep function do on the boiler? Is it like a self-cleaning oven function?

GW

Yes chimney button is “high fire” 

SJC

I installed my 142 about 11 years ago, and runs great, but yes, cleaning those fins on the heat exchanger has been a huge problem.

Initially, to make sure my warranty was going to be valid, I paid to have my local 'Buderus Expert' company check over my installation and verify all was according to specs, etc. And then I signed up for annual service agreement, which included the annual cleaning.

All went well those first years, and yes, he did the mineral oil/high burn/reclean method, as was specified on most any Buderus site at the time. But then another person came out and said, "Oh, these run so clean that you don't need to do that every year. I went along with the 'expert' telling me that. And then the next year, he said it again, that the unit really didn't need to be cleaned like that, and he just turned it on high burn/chimney without opening up anything. Yeah.

So, the next year, another guy came out and opened it up and said, "WHOA!" That it was so clogged that he couldn't clean it using the mineral oil method, etc., and said that the only way for him to clean it was for ME to pick away at all that crust and open up the airways so he could do the oil cleaning. Yeah.

Of course I was livid on the phone to the company, and they gave me a free year of service. By this time, as it was running out of being in warranty, I figured I might as well start cleaning it myself, using my manual pick/steel brush method. 4 hours of my time, but I had those fins looking great! And I've been doing that ever since.

Well, this year I noticed that the mineral oil method didn't seem to be pushed. And since I had cleaned my A/C system using coil cleaner, and since it clearly was designed to clean aluminum, I figured after picking away the big stuff for an hour that I would try using that. Good old Sodium Hydroxide.

I sprayed it on very carefully, over/under/through, let it sit for a few minutes (I was nervous about it eating away at the heat exchanger) and then used a squirt bottle, filling over and over, then finally just pouring over all the fins. (And yes, I had plastic over the electronic and 3 old bath towels underneath.) Mess on the concrete mechanical room floor, but clearly white liquid and softened remains on the coils! I let it all dry and then did it again, about 5 minutes, then flushed off a LOT. (Really worried I might be leaving something on that heat exchanger that would eat through.) A light rubbing of the Hit Surface Ignitor with emery cloth, and then put everything back together. (Next year I'll try the coil cleaner on the REALLY crusty bottom drainage pan that I've been doing with chisels and wire brushes in my drill.)

Time will tell if I've done something horrible to that heat exchanger. It just seems like if you could just use coil cleaner, everyone would have been using that.

Btw, additional hint: A lot of people crack that condensate trap by yanking it out and splitting the opening. (One of my 'experts' did that, and I repaired it by melting the plastic with a Weller craft tip on a soldering gun, then put a nylon zip tie to reinforce that opening. What I now do is keep the trap attached until I'm pulling the bottom drain pan away, then pull it off and put aside. Saves stressing that neck and eventually buying a new one for $100.)

The spare parts I keep nearby include a couple heads for the zone valves, a Hot Surface Ignitor when this one eventually dies, and a set of gaskets for the upper and lower pans. I have a new On/Off Power Switch still backordered, but I have the unit plugged in and the switch locked closed for now.

Big Ed_4

You use butcher block oil not mineral oil , there is a difference ….. Just don't ask me what :)

delcrossv

https://forum.heatinghelp.com/discussion/comment/1813903#Comment_1813903

Price. :D